Fingers crossed for Obama

In three months' time, George Bush will be back on his ranch in Texas - to the world's relief as well as, increasingly plainly, his own. He may have spoken some wise words about internationally coordinated action against the global financial crisis after meeting G7 finance ministers at the White House on Saturday, but he is rapidly becoming part of the past. In 22 days, Americans will select his successor. The responsibility of leading the United States and the developed world through these increasingly grim times will soon fall to either Barack Obama or John McCain.

Unless the current opinion polls are seriously wrong - or unless something new and decisive occurs in the campaign before November 4 - it seems likely that the responsibility will fall on Mr Obama's shoulders. Mr McCain built a strong position during the summer and came out of the conventions with a powerful bounce, largely caused by the novelty of his selection of Sarah Palin as his running mate. But as the final phase of the campaign got under way and with voters at last bending their minds to the long-running contest everything has moved consistently Mr Obama's way. The national polls currently give him an average lead of around seven points. This lead, moreover, is growing - the latest Newsweek survey has Mr Obama with an 11-point lead, while a Fox News survey has Mr McCain dipping as low as 39% among registered voters. Polls also show Mr Obama ahead in several swing states and competitive in states that normally vote for the Republican nominee.

This is partly because the Palin candidacy has been exposed for what it is, a political firework rather than an electoral rocket that would carry Mr McCain to the White House. This has happened less because of the Troopergate inquiry or some sharp television satires - though neither of these has helped - than simply because the Alaska governor's credentials have been increasingly held up to the light. The simple truth is that Mrs Palin has been found wanting as a potential president. Mr McCain's chances of becoming the oldest president to take office in US history have been relentlessly undermined by the manifest inadequacy of the person who would succeed him if age or infirmity suddenly took their toll, and because that choice reflects so lamentably on Mr McCain's own judgment.

The much larger factor, however, is the economy. The more that American voters have focused on their economic woes, the more decisively the presidential contest has shifted in Mr Obama's favour. This is partly because the Republicans are so deeply associated with the economic philosophy that is now in institutional freefall, partly because the Democrats are, in general terms, still the party of federal action to defend the disadvantaged, partly because the accelerating downturn has happened on the watch of a generally unimpressive Republican president and partly because Mr Obama has handled economic questions with more skill and substance in his debates with Mr McCain. Yet Mr Obama has also been careful to keep the dramas in Washington and on Wall Street at arm's length. The next president will face the most daunting economic agenda since Franklin Roosevelt. It is far from clear how Mr Obama - who regularly drops protectionist hints - would tackle this global recession.

Right now, of course, his priority is simply to get elected. The exchanges are turning dirtier - again to the McCain campaign's shame - and the great unspoken question of Mr Obama's race seems likely to play an even more prominent part in the final phase. If the 2008 election becomes reframed as another culture wars contest then the current gap may narrow. As long as the economy is not just the main issue in voters minds but, as now, the overriding one, then it seems that Mr Obama will win. If he does, it will be a marvellous moment. But it will also be the moment when the real work starts.